Video processing systems used for editing video generally provide a set of effects and other operations that may be combined in various ways to create a video program. Due to the wide variety of combinations of operations that might arise during editing, most video processing systems have a limit to the combinations of operations that can be performed in real time. If the architecture of the video processing system is fixed and well-known, then this limit can be easily defined. In systems with flexible architectures, such as those with flexible hardware architectures or those that combine software and hardware-based processing, it can be difficult to characterize performance of the system, and thus to determine whether a set of operations can be performed in real time.